The need for a significantly protective helmet of reduced bulk and very thin silhouette has existed for many years in several athletic and entertainment sports, and in some cases, military applications. The purposes creating this need and which such a helmet should provide are maximum maneuverability or very low aerodynamic resistance depending on the helmet's intended use. Protection of the wear's head from impacts however, remains a priority over this need. The prior art consistently demonstrates this priority being provided for by the use of substantially unitary, rigid outer shells. These shells, normally lined with a variety of impact absorbing materials, must be constructed large enough to accommodate additional padding structures or lining assemblys primarily for the purpose of responding to the wearer's head shape, and to a limited degree, the size of the wearer's head. The use of such padding or structures therefore, requires a corresponding increase in the helmets's overall bulk adversely affecting it's dimensional profiles, stability, and aerodynamic resistance. The conflict between the priority of providing adequate protection and the need for a helmet of very low bulk or aerodynamic resistance has been approached by the prior art only indirectly on a very limited basis. Attempts to provide a solution to this problem have incorporated the use of flexible or elastic fabric. Typical of this approach for example, is that shown in U.S. Pat. Nos. 3,784,984 (1974) to Aileo and 4,023,209 (1977) to Frieder, Jr. et al. In these patents a helmet liner is constructed of fabric mesh formed into pockets into which a series of energy absorbent pads are inserted. The use of elastic mesh in these helmets is intended to provide some degree of flexible response to the wearer's head shape and size. This ability however, is severely contradicted by the copious use of non-elastic reinforcing tapes at the margins of various panels, restricting the elastic function of those panels.
The most significant problem inherent in the prior art however, as exemplified in part by the above patents, is the vulnerability to impacts at locations where various padding structures are approximately adjacent with intentional spacing. The problem also occurs at the margins and regions of internal earcup assemblys utilized for sound attenuation and communications in military applications. This weakness also occurs in a similar manner at indentations in a single unitary pad as shown in U.S. Pat. No. 4,843,642 (1989) to Brower. An increased degree of abutment of sections is claimed to occur at these indentations upon a radial impact to adjacent sections. Although the helmet dispenses with the use of an overlying outer shell, no feature is present to protect the wearer's head form impacts at the locations of these indentations.
Recognizing these vulnerabilitys, the prior art teaches that provision for full impact protection must revert to the concept of the use of rigid, substantially unitary outer shells or an assembly of parts embracing this approach. Due to the relatively inflexible nature of these shells they present an increased overall bulk in their silhouette with a corresponding increase in weight and diminished maneuverability. They do not present streamlined compact conformity to the wearer's head, but rather, objectionable encumbrances in that regard. In the above patents where the wearer is provided the option of foregoing the use of these outer shells, offered as demountable accessories, the wearer must endure the inconvenience of additional inventory, transport and assembly of multiple components for full protection.